Abstract
The DLR Earth Sensing Imaging Spectrometer (DESIS) is a new hyperspectral instrument developed by the German Aerospace Agency (DLR) and operated under the collaboration of DLR and Teledyne Brown Engineering (TBE). It is mounted on International Space Station (ISS) and has a ground sample distance of 30 m and a swath of 30 km. It has 235 spectral channels that measure across the spectral range from 400 nm and 1000 nm with a spectral sampling of approximately 2.5 nm. This study performs the radiometric assessment of DESIS by cross comparing it with a well-calibrated sensor such as Landsat 8 Operational Land Imager (OLI) and Sentinel 2A Multispectral Instrument (MSI). The cross-comparison between DESIS and Landsat 8 OLI and Sentinel 2A is performed by using the three and two coincident collects between the sensor pairs respectively. From these three coincident collects between DESIS and Landsat 8 OLI, 17 regions of interest (ROI’s) of different surface types and intensity levels are chosen for cross-comparison. Initial analysis shows that there is a very good agreement between DESIS with Landsat 8 OLI. The mean of reflectance difference between DESIS and Landsat 8 OLI is within 0.015 reflectance unit and approximately 7% (in relative scale) across all the bands. Similarly, for DESIS and Sentinel 2A cross-comparison, two coincident collects from Libya 4 CNES ROI are used. The difference between these two sensors is within the 0.015 reflectance unit across all the bands. These initial results show that DESIS has a very good agreement with both Landsat 8 OLI and Sentinel 2A MSI.
Cross Comparison of DESIS with Landsat 8 OLI and Sentinel 2A MSI
The DLR Earth Sensing Imaging Spectrometer (DESIS) is a new hyperspectral instrument developed by the German Aerospace Agency (DLR) and operated under the collaboration of DLR and Teledyne Brown Engineering (TBE). It is mounted on International Space Station (ISS) and has a ground sample distance of 30 m and a swath of 30 km. It has 235 spectral channels that measure across the spectral range from 400 nm and 1000 nm with a spectral sampling of approximately 2.5 nm. This study performs the radiometric assessment of DESIS by cross comparing it with a well-calibrated sensor such as Landsat 8 Operational Land Imager (OLI) and Sentinel 2A Multispectral Instrument (MSI). The cross-comparison between DESIS and Landsat 8 OLI and Sentinel 2A is performed by using the three and two coincident collects between the sensor pairs respectively. From these three coincident collects between DESIS and Landsat 8 OLI, 17 regions of interest (ROI’s) of different surface types and intensity levels are chosen for cross-comparison. Initial analysis shows that there is a very good agreement between DESIS with Landsat 8 OLI. The mean of reflectance difference between DESIS and Landsat 8 OLI is within 0.015 reflectance unit and approximately 7% (in relative scale) across all the bands. Similarly, for DESIS and Sentinel 2A cross-comparison, two coincident collects from Libya 4 CNES ROI are used. The difference between these two sensors is within the 0.015 reflectance unit across all the bands. These initial results show that DESIS has a very good agreement with both Landsat 8 OLI and Sentinel 2A MSI.